Kad mi se ne govori, samo klimnem i pošaljem kratku poruku.

Here Kad most naturally means when or whenever.

Because the sentence describes what the speaker typically does in that situation, English could translate it as either:

• When I don’t feel like talking...
• Whenever I don’t feel like talking...

So kad often introduces both a specific time and a general repeated situation.

Also, kad and kada both mean when. Kada is just the fuller form; kad is very common in everyday speech.

This is a very common Croatian pattern for expressing a feeling, urge, or inclination.

• govori mi se = I feel like talking
• ne govori mi se / mi se ne govori = I don’t feel like talking

So this is not the same as:

• ne govorim = I am not speaking / I don’t speak

The sentence is about desire or willingness, not about the literal action already happening.

This pattern is similar to:

• spava mi se = I feel sleepy / I feel like sleeping
• jede mi se = I feel like eating
• pleše mi se = I feel like dancing

Mi is the short dative form of ja.

Here it means something like to me, but in natural English we usually do not translate it literally. It marks the person experiencing the feeling.

So:

• govori mi se literally = talking is felt to me
• natural English = I feel like talking

This dative experiencer is very common in Croatian with feelings, urges, and bodily states.

In this sentence, se is part of an impersonal/reflexive construction. It is not reflexive in the straightforward sense of myself/yourself.

So govoriti se here does not mean to talk oneself. Instead, se helps create the idiomatic pattern:

• govori mi se = I feel like talking

You should learn this whole structure as a unit. The same thing happens in expressions like:

• jede mi se
• spava mi se
• radi mi se

So yes, se is important, but the best way to understand it is as part of this fixed Croatian pattern.

Because the construction is impersonal.

There is no normal subject like ja doing the action in the usual way, so Croatian uses 3rd person singular:

• govori mi se
• jede mi se
• spava mi se

That does not mean the subject is he/she/it. It is just the standard form used in this kind of expression.

So even though the meaning is about I, the verb stays in 3rd person singular because the grammar of the structure is impersonal.

Both mi and se are clitics: short unstressed words that usually appear very early in the clause.

In Croatian, clitics often go in the second position of the clause, so after Kad you get:

• Kad mi se ne govori...

Also, the order of clitics matters. In this combination, mi comes before se, not the other way around.

So:

• mi se = correct
• se mi = not correct here

This word order may feel unusual to English speakers, but it is very normal in Croatian.

Because Croatian usually drops subject pronouns when they are not needed.

The verbs already show the person clearly:

• klimnem = I nod
• pošaljem = I send

So adding ja is usually unnecessary unless you want emphasis or contrast.

That is why the sentence sounds natural without ja.

This is about aspect.

• klimnem is perfective
• pošaljem is perfective

They describe a single complete action:

• klimnem = I give a nod
• pošaljem = I send off

In this sentence, the speaker means that whenever that situation happens, they respond with one quick completed action: a nod, and a short message.

If you used the imperfective forms:

• klimam
• šaljem

the meaning would feel more like an ongoing, repeated, or habitual process, not one compact response.

So the perfective forms fit well because the actions are short and completed each time.

Because poruku is the direct object of pošaljem, so it has to be in the accusative case.

Base form:

• kratka poruka = a short message / short message in the nominative

In the sentence:

• pošaljem kratku poruku = I send a short message

Both the adjective and the noun change to match the accusative feminine singular:

• kratka → kratku
• poruka → poruku

So kratku poruku is the correct object form.

Yes, it is standard and correct.

The first part:

• Kad mi se ne govori

is a subordinate clause introduced by kad.

The second part:

• samo klimnem i pošaljem kratku poruku

is the main clause.

When the subordinate clause comes first, Croatian normally separates it with a comma:

• Kad mi se ne govori, samo klimnem i pošaljem kratku poruku.

Samo here means just or simply.

It shows that the speaker does only a minimal response:

• samo klimnem = I just nod
• i pošaljem kratku poruku = and send a short message

So it gives the sentence the sense of that’s all I do in that situation.